A foreign object left inside an F-35 engine at Luke Air Force Base, Arizona, in early 2023 caused nearly $4 million in damages, a recent Air Force accident investigation report revealed.
The item — a handheld flashlight — was sucked into the engine’s air intake during a maintenance ground run on the night of March 15, Air & Space Forces Magazine first reported. The aircraft belonged to the 56th Fighter Wing.
During an idling procedure, a team of three maintainers started the engine without issue before going through typical checks, including idling for five minutes to monitor for fuel leaks.
It wasn’t until the airmen turned off the engine that anything seemed amiss. During the shutdown, one maintainer noted “abnormal noises.” None of the airmen were injured.
One of the maintainers carried out a tool inventory check after installing a “metering plug into an engine fuel line,” the investigation noted. The process took place before another maintainer used the flashlight to carry out a “Before Operations Servicing” inspection, the report said.
Investigators determined that the maintainers’ lack of adherence to standard cautionary items highlighted in the Joint Technical Data checklist before the run contributed to their leaving the flashlight behind.
Investigators also found that “complacency” related to the F-35′s Autonomic Logistics Information System, or ALIS, is partly to blame.
“The substantial number of checklists and difficulty in accessing the correct ones causes complacency when users reference the required maintenance procedures,” the report noted.
Ultimately, the mishap damaged the aircraft’s second stage rotor, third stage rotor, fifth stage rotor, sixth stage rotor, fuel nozzle, bypass duct, high pressure compressor, high pressure turbine and fan inlet variable vane, the report found.
In total, the estimated cost of damages associated with the accident came in at $3,933,106.
The report concluded that the inspecting maintainer “failed to clear the inlet of foreign objects after completing the required inspections for an engine run after they exited the aircraft inlet.”
“Failure to complete checklist tasks resulted in a flashlight being left inside the inlet,” the report said.
Sarah Sicard is a Senior Editor with Military Times. She previously served as the Digitial Editor of Military Times and the Army Times Editor. Other work can be found at National Defense Magazine, Task & Purpose, and Defense News.